Surface mount technologies are used in high volume electronics to mount integrated circuits (“ICs”) and other active and passive components to a substrate, such as a printed circuit board (“PCB”). Solder paste is applied to solder pads that have been formed on the substrate, the components are precision-placed over the solder pads so that they are temporarily adhered to the pads by the solder paste, and then heat is applied to melt the paste and complete the solder connections between pins on the components and aligned solder pads on the PCB.
Often the solder is the only physical connection between the component and the PCB. This physical connection is generally sufficient, particularly where the component is small, multiple soldered connections exist between the component and the PCB, and the PCB is used in a benign environment generally free of vibration, shock, and other physical stress. However, to strengthen the attachment and enhance the durability of the solder connections, it is known to include on the bottom of a component an additional plate or tab, not used for electrical interconnection, to provide an additional area of solder bonding.
The use of surface mount technologies allows components to be mounted quite close together on the substrates. The resulting high component density is desirable, but can increase the risk that solder bridges will be formed at unplanned, and unwanted locations on the PCB. Where an additional tab is provided on a component to enhance bond strength, the tab will unfortunately create additional opportunities for unwanted solder bridges to arise.